Extremely Slow Backups

[Vinnie_Ghika]

I am running BE 9.1 on a brand new HP Proliant server. We recently replaced the old server and used the same BE license to install onto the replacement. I have applied BE SP4a and the latest tape device drivers. We did not move over the tape drive from the old server, it was replaced with a new internal HP DLT VS160 drive, connected to the on-board SCSI controller. No other devices are on either on-board SCSI channel. The drives are on their own RAID controller. The OS is Windows Server 2000, SP4.

My problem is that the backups are extremely slow. It takes well over 48 hours to backup 60G of data. This is with no Exchange information selected.

I have already gone through document 249090 and got no results from it. I have not changed any of the drive properties because I feel that it won't help.

Backups are basically not runnning so a response soon would be greatly appreciated.

Thanks in advance,

[Amorphous_Sage]

Hi, did you run up the HP Tape Tools program yet? this allows test runs of data to be sent to the drive (you canchoose how much/compression etc.). This will give you a feel for weather its Backup Exec or something external to it (like the driver or ther setting).

[Neville_Turner]

Hi. Question: I know your problem arises without adding exhange information, but is exchange itself installed on the machine thats hosting the backups? If so, check that your database maintenance timeframe falls outside that of your backups - ie, work out approximately how long your backups should take (with your drive, 60Gb shouldnt take more than a couple hours). Then reschedule the maintenance for a time before your backups (by default it runs between 1-5am i think).

If not, try unchecking the verify option and make sure its using "hardware compression, otherwise none". Use those settings and check the time it takes.

[Vinnie_Ghika]

Ok, I tried running Tape Tools and all diag tests returned successful. The firmware of the drive was already current. As for Exchange, yes it is installed but I manage several other clients with similar configurations and backup with much better performance on an inferior tape drive. With a small Exchange database, the maintenance should not degrade performance of backups as noticable as what I am seeing.

One question: Can Removable Storage affect performance on a single drive, or is only a problem with libraries?

-Vinnie

[Ken_Putnam]

Are the slow backups local, or remote or both?

If network, check to make sure that at least one end of each pipe between the server(s) is hardset, not Autonegotiate on both ends. I prefer to hardset both ends

if local only or both -
From the devices tab, right click the drive, properties, what are the settings for block size, buffersize, number of buffers, etc?

[Vinnie_Ghika]

Local only. The settings are default.

[Ken_Putnam]

What are the specfic numbers?
Is the tape drive the only thing on the SCSI card, or at the very minimum, the only thing on the Channel?

[Sharvari_Deshmu]

Hello,

We request you to update us regarding this issue.


Thanks,

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[Vinnie_Ghika]

Apparently the settings were not default even though they were not changed. When I clicked the "default settings" button, it changed them to what appears to now be default. They were as follows, Block Size-1k, Buffer Size-32k, Buffer Count- 10 and High Water-7.

As I originally posted, the drive is on a non-raid channel by itself.

[Ken_Putnam]

That 1K block size will absolutely kill throughput. BackupExec writes 1K of data, stops, skips a short space, writes another 1K, stops etc.

Set the block size to the max that your device will support - usually either 32K or 64K. Set the buffer to at least 128K, test then try 256K. Number of buffers try starting at 10

let lus know how things go

[Vinnie_Ghika]

You know, while I was writing down the information, 1k didn't strike me as all that effecient. That's why I clicked the default button and it changed it to 64k block and buffer. I never really looked at it before becuase I didn't change it. ANyway, I will keep you informed...

[Vinnie_Ghika]

As you probably would have guessed, that fixed the problem. The backup completed in under 2 hours. I appreciate the help.